If a sodden rice paddy feels soft and forgiving underfoot, it is not a merciful place to set down an airplane at 200 mph. And that’s only one of Mike Selby’s reasons to look nervous as he watches his A-10 Warthog—a 10-foot-wide, 65-pound, hand-built model—begin its maiden takeoff roll down a rough asphalt runway near Bangkok, Thailand. Selby, who spent over $12,000 and the better part of a year fabricating and building this radio-controlled jet, stands runwayside with his thumbs hooked into the belt loops of his jeans, trying to look relaxed as he draws on a Cuban cigar.